Gaseous
oxygenated
organic
molecules
(OOMs)
are
crucial
precursors
of
atmospheric
aerosols.
OOMs
in
urban
atmospheres
have
complex
compositions,
posing
challenges
to
understanding
their
formation,
evolution,
and
influences.
In
this
study,
we
identify
2403
gaseous
Beijing
using
online
nitrate-based
chemical
ionization
Orbitrap
mass
spectrometry
based
on
one-year
measurements.
We
find
that
can
be
identified
with
higher
accuracy
wider
coverage,
compared
previously
used
spectrometry.
With
optimized
OOM
resolving
capabilities,
previous
knowledge
expanded.
First,
clear
homologous
oxygen-addition
characteristics
the
revealed.
Second,
lower
concentrations
or
masses
characterized
high
confidence,
e.g.,
above
350
Da.
particular,
dimers
(e.g.,
C
Atmospheric chemistry and physics,
Journal Year:
2024,
Volume and Issue:
24(8), P. 5117 - 5147
Published: April 30, 2024
Abstract.
Accounting
for
the
condensation
of
organic
vapors
along
with
water
vapor
(co-condensation)
has
been
shown
in
adiabatic
cloud
parcel
model
(CPM)
simulations
to
enhance
number
aerosol
particles
that
activate
form
droplets.
The
boreal
forest
is
an
important
source
biogenic
vapors,
but
role
these
co-condensation
not
systematically
investigated.
In
this
work,
environmental
conditions
under
which
strong
co-condensation-driven
droplet
enhancements
would
be
expected
over
biome
are
identified.
Recent
measurement
technology,
specifically
Filter
Inlet
Gases
and
AEROsols
(FIGAERO)
coupled
iodide-adduct
chemical
ionization
mass
spectrometer
(I-CIMS),
utilized
construct
volatility
distributions
atmospheric
organics.
Then,
a
suite
CPM
initialized
comprehensive
set
concurrent
observations
collected
Finland
during
spring
2014
performed.
degree
impacts
formation
dependent
on
initialization
temperature,
relative
humidity,
updraft
velocity,
size
distribution,
concentration,
distribution.
predicted
median
concentration
(CDNC)
due
accounting
organics
fall
average
between
16
%
22
%.
This
corresponds
activating
10–16
nm
smaller
dry
diameter
otherwise
remain
as
interstitial
aerosol.
highest
CDNC
(ΔCDNC)
presence
nascent
ultrafine
mode
geometric
mean
∼
40
no
clear
Hoppel
minimum,
indicative
pristine
environments
(e.g.,
via
new
particle
processes).
Such
observed
30
%–40
time
studied
environment
when
frequency
highest.
To
evaluate
frequencies
such
experienced
by
Earth
system
whole
biome,
5
years
UK
System
Model
(UKESM1)
further
used.
substantially
lower
than
those
at
site
(<
6
time),
positive
values,
peaking
spring,
modeled
only
Fennoscandia
western
parts
Siberia.
Overall,
similarities
limited,
limit
ability
model,
or
any
similar
representation,
project
climate
relevance
forest.
For
critical
distribution
regime,
ΔCDNC
sensitive
concentrations
semi-volatile
some
intermediate-volatility
compounds
(SVOCs
IVOCs),
especially
overall
surface
area
low.
magnitudes
less
affected
more
volatile
formic
acid
extremely
low-
low-volatility
(ELVOCs
LVOCs).
reasons
most
condense
inefficiently
their
high
below
base,
LVOCs
ELVOCs
too
low
gain
significant
soluble
reduce
supersaturations
enough
activation
occur.
A
reduction
supersaturation
caused
emerges
main
driver
ΔCDNC.
results
highlight
potential
significance
close
sources
fresh
particles.
accurate
predictions
effects
CDNC,
also
larger-scale
models,
representation
critical.
Further
studies
targeted
finding
observational
evidence
constraints
field
encouraged.
Analytical Chemistry,
Journal Year:
2024,
Volume and Issue:
96(21), P. 8604 - 8612
Published: May 1, 2024
Chemical
ionization
(CI)
atmospheric
pressure
interface
mass
spectrometry
is
a
unique
analytical
technique
for
its
low
detection
limits,
softness
to
preserve
molecular
information,
and
selectivity
particular
classes
of
species.
Here,
we
present
fast
polarity
switching
approach
highly
sensitive
online
analysis
wide
range
trace
species
in
complex
samples
using
selective
CI
chemistries
high-resolution
spectrometry.
It
achieved
by
successfully
coupling
multischeme
chemical
inlet
(MION)
an
Orbitrap
Fourier
transform
spectrometer.
The
capability
flexibly
combine
from
both
polarities
effectively
extends
the
detectability
compared
only
one
chemistry,
as
commonly
used
positive
negative
reagent
ions
tend
be
different
We
tested
performance
MION-Orbitrap
reactive
gaseous
organic
generated
α-pinene
ozonolysis
environmental
chamber
standard
mixture
71
pesticides.
Diethylammonium
nitrate
are
polarities.
show
that
with
resolving
power
280,000,
can
switch
measure
within
1
min,
which
sufficiently
stable
follow
temporal
evolution
thermal
desorption
profile
detected
23
pesticides
ion.
Facilitated
switching,
also
47
diethylammonium,
improving
total
number
59.
For
ozonolysis,
combining
diethylammonium
addresses
need
oxygenated
molecules
environments
oxidation
states.
These
results
indicate
promisingly
serve
versatile
tool
nontargeted
various
applications.
ACS ES&T Air,
Journal Year:
2024,
Volume and Issue:
1(8), P. 848 - 859
Published: May 21, 2024
Volatile
organic
compounds
(VOCs),
released
from
both
natural
and
anthropogenic
activities,
undergo
oxidation
in
the
atmosphere
to
form
alkyl
peroxy
radicals
(RO2)
that,
through
subsequent
chemistry,
a
variety
of
oxygenated
species
that
may
impact
air
quality
climate.
Among
potential
formed
are
nitrates
(ON)
can
be
transported
over
long
distances
contribute
ozone
production
particle
formation.
The
atmospheric
lifetime
an
ON
is
influenced
by
its
molecular
structure.
structure
impacts
further
gas
phase
reaction
(e.g.,
photolysis
photo-oxidation
with
OH
radical
reaction)
gas-to-particle
partitioning
result
multiphase
chemistry
hydrolysis)
secondary
aerosol
(SOA)
This
study
investigates
two
atmospheric-relevant
ON,
specifically,
hydroxy
nitrates,
2-methyl-1-nitrooxy-3-buten-2-ol
(C5H9NO4,
-ONO2,
C5-ON),
3-methyl-2-nitrooxy-4-penten-3-ol
(C6H11NO4,
tertiary
C6-ON).
Significant
differences
their
reactivity
demonstrated,
C5-ON
underwent
faster
photolysis,
while
C6-ON
was
more
resistant
whereas
degradation
during
OH-initiated
photo-oxidation.
These
attributed
presence
extra
methyl
group
on
C6-ON.
Furthermore,
products
demonstrate
complexity
processes
were
detected
chemical
ionization
Orbitrap
mass
spectrometry
operated
negative
mode.
Notably,
cleavage
O–N
bond
alkoxy
dominant
pathway
addition
followed
RO2
bimolecular
reactions
(i.e.,
+
or
HO2)
oxidation.
research
sheds
light
intricate
atmosphere,
emphasizing
role
fate.
Abstract.
Climate
extremes
are
projected
to
cause
unprecedented
deviations
in
the
emission
and
transformation
of
volatile
organic
compounds
(VOCs),
which
trigger
feedback
mechanisms
that
will
impact
atmospheric
oxidation
formation
aerosols
clouds.
However,
response
VOCs
future
conditions
such
as
extreme
heat
wildfire
events
is
still
uncertain.
This
study
explored
modification
mixing
ratio
distribution
several
anthropogenic
biogenic
a
temperate
oak–hickory–juniper
forest
increased
temperature
transported
biomass
burning
plumes.
A
chemical
ionization
mass
spectrometer
was
deployed
on
tower
at
height
32
m
rural
central
Missouri,
United
States,
for
continuous
situ
measurement
from
June
August
2023.
The
maximum
observed
region
38
°C,
during
multiple
episodes
remained
above
°C
hours.
Biogenic
isoprene
monoterpene
followed
closely
daily
profile
but
varying
rates,
whereas
were
insensitive
elevated
temperature.
During
period,
emissions
site
substantially
ratios
acetonitrile
benzene,
produced
biomass.
An
in-depth
analysis
spectra
revealed
more
than
250
minor
compounds,
formamide
methylglyoxal.
overall
volatility,
O:C,
H:C
extended
list
responded
changes
presence
combustion
Multivariate
also
clustered
into
five
factors,
highlighted
sources
unaccounted-for
VOCs.
Overall,
results
here
underscore
imminent
effect
VOC
variability,
important
understanding
interactions
between
climate
chemistry.
Gaseous
oxygenated
organic
molecules
(OOMs)
are
crucial
precursors
of
atmospheric
aerosols.
OOMs
in
urban
atmospheres
have
complex
compositions,
posing
challenges
to
understanding
their
formation,
evolution,
and
influences.
In
this
study,
we
identify
2403
gaseous
Beijing
using
online
nitrate-based
chemical
ionization
Orbitrap
mass
spectrometry
based
on
one-year
measurements.
We
find
that
can
be
identified
with
higher
accuracy
wider
coverage,
compared
previously
used
spectrometry.
With
optimized
OOM
resolving
capabilities,
previous
knowledge
expanded.
First,
clear
homologous
oxygen-addition
characteristics
the
revealed.
Second,
lower
concentrations
or
masses
characterized
high
confidence,
e.g.,
above
350
Da.
particular,
dimers
(e.g.,
C
